I am noticing a drop from 325-340 km/45L to 250-270/45L, same style of driving (90% city), new o2, plugs, yada yada, same S-AFC settings, etc

that's going from 13.6L/100 to about 17L/100

I am gonna switch from Ultra94 to Shell V-91 and see if I can feel a difference, its winter and boost is low anwyay (12psi)

seems to happen every year w/ winter gas, and its not due to excessive warm up time, etc. I don't idle it much, 20 sec after start up I drive gently until it reaches operating temp

I've noticed it but I idle it for about 4-5 minutes so I figure that's the reason.....if I don't I'll shred what's left of my 2nd gear syncro.

I think there are multiple factors. Driving through snow eats up more gas. Snow tires get worse gas mileage. Car takes longer to get up to operating temp, and make sure your tires aren't underinflated when the temp drops.

I have seen mine drop a bit but not that much

if the air volume calculation system, whatever it is, is not calibrated for lower temps then it might not compoensated for denser air.

My last tank in the new FWD was with "winter" gas, and I got nearly 600kms took about 56L from "empty" afterwards.
This was on winter tires as well, and in the mornings, I let her idle for 2-3 mins before driving.

It is the gas itself. The additives used to prevent gasline freezing don't burn as well and have less energy than in summer fuel. Less energy means you have to use more fuel for the same result.

Well I used to get 300km on a full tank of Ultra 94, and I am still about the same in the winter, but I run 19PSI, 550cc injectors 255walbro and a 2g mas, so that might explain it, but I am not complaing my old V6 and V8 cars/trucks got 300km a tank but it took twice as much to fill the thing up.

300kms to a tank of how many litres? If you are getting 300kms to 55ishL of 94, than something is seriously wrong with your car, your driving habits, or you sit in traffic 99% of the time. I reckon there aint too much traffic in New Hamburg though =).
Even a modded DSM should see at least 450kms to a tank if driven somewhat sensibly, probably need to work on tuning the car rather than just slapping Go-fast crap on...

I've lost about 50km per tank in my Civic.

I am lucky to see 300kms in the city stock in the summer. My car is tuned and running good now. I have talked to other guys who are getting about the same. Thats always with premium 91 octane. I have to go to the outskirts of town to get the 94 octane so seldom do I get to use that stuff. How many litres to a 2G AWD tank. Anybody know.

You should be able to get at least 55L in there Ryan, its probably rated around 60ish though. 16 US gallons.

so far I think its the gas

filled up w/ shell v-91, and I have used up 1/4, and odometer shows 120km, w/ sunoco I am very near the middle mark after 120km, I will know for sure by the end of the week when I use it all up

My heavily modified DSM gets 450kms/tank on Ultra94 and 500+ wit Petro Canada Premium.

That's because Sunoco uses more Ethenol in their gas.

Is their an advantage to more Ethenol?

Higher octane rating?

Not higher octane raiting. It's an addiditve that is combustable like gasoline. They use it to help spread the costs of using 100% gasoline.

Ethanol burns cleaner.

So its a filler that evaporates quickly. What's the point of Sunoco gas?

Also What's the advantage (if any) of Sunoco gas over say petro-can or shell?

91 to 94 octaine rating. Altough 91 should be fine for 12-15psi but for us running 20-30psi street 94 is a must.

ethanol is an alcohol made of natural sources.

There is some incentive to use more ethanol and both Canada and the US do have plans to introduce more ethanol in the fuel cycle.

it burns cleaner.


But I can't see how the ethanol could have such a 30% difference only in winter. Ethanol is used in the summer as well. I am notr sure about the percentage but it is there.

I go out of my way to stay off highways and take back roads due to the AWD + winter tire advantage. Hell, I turn a 10 minute trip into an hour long adventure all the time. I figure that's why.

2G's have a 64L tank (according to spec)...not sure about 1G's...

I've never been able to fill up with more than 49 Litres in my 1G...although my "empty" line may be completely off.

I get about 350kms city to 45-46 litres of gas (ultra 94). Summer and winter make maybe a 10km difference for me.

Highway, I can squeeze out about 520kms or so from the same.

I'm pretty hard on the car in the city

Your empty line must be off. I've been able to squeeze 58L in my 1G.

My city driving is about 11L/100KMs

1.8L with close to 290,000KM...not too bad

I get 10L/100kms...

I am not sure, I get about 9 in city with AWD Turbo Galant and **** load of leaks. and yeah, my car has almost as much on it.

AMEN!

I leave for work early just so that I can have more of the road to myself. Mainly because I'm sideways so much.

[EDIT]
Oops, forgot about the thread topic.

Winter is hit & miss for me but anywhere between 11-13 L/100km. Summer is always 9-11 L/100km unless I put the brick on the accelerator. Don't notice a difference in gas except for knock. I just stick with 94 year round.

For those interested in the details: 1Ga, AWD, rewire, 14b@14psi, Hakka2's 195-65-15, 3" exhaust.

[/EDIT]

so last fill up I used shell & got 300~310km/46L

with sunoco I got 250-270 so I conclude that sunoco gas dries up a heck of a lot quicker in the winter time

In the summer time I haven't noticed a difference yet, although this summer I will pay closer attention.

What mods do you have? You're up around 15L/100km with the Shell. Are you running rich?

Thats interesting.

I just filled up and zeroed the trip meter a few days ago. When it gets to half, I'll see how far 30L or so gets me.

I am pretty sure I am running rich, but if I lean it anymore I get knock, and if I retard the timing anymore, it bogs and EGTs go up through the roof

It maybe fuel pressure related, the 255 walbro maybe too uch for the stock FPR, gonna install the regulator and lower the press. to spec and see

my car never acted right with the stock FPR and the 255HP.

I doubled the FPR and later dropped a stock pump in. for a stock car like mine that was a good idea.

I rewired my 255HP pump, and boy, did that ever screw up the fuel trims.